$ { {-3} \times \left[\begin{array}{rrr}{-1} & {0} & {-2} \\ {0} & {1} & {-1}\end{array}\right] = {?} } $
Solution: To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rrr}{-3}\times{-1} & {-3}\times{0} & {-3}\times{-2} \\ {-3}\times{0} & {-3}\times{1} & {-3}\times{-1}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{3} & {0} & {6} \\ {0} & {-3} & {3}\end{array}\right]}$